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  • 101.
    Hällqvist, Robert
    et al.
    Systems Simulation and Concept Design, Saab Aeronautics, Linköping, Sweden.
    Schminder, Jörg
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering.
    Eek, Magnus
    Systems Simulation and Concept Design, Saab Aeronautics, Linköping, Sweden.
    Braun, Robert
    Linköping University, Department of Management and Engineering, Fluid and Mechatronic Systems. Linköping University, Faculty of Science & Engineering.
    Gårdhagen, Roland
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering.
    Krus, Petter
    Linköping University, Department of Management and Engineering, Fluid and Mechatronic Systems. Linköping University, Faculty of Science & Engineering.
    A Novel FMI and TLM-based Desktop Simulator for Detailed Studies of Thermal Pilot Comfort2018In: ICAS congress proceeding, International Council of the Aeronautical Sciences , 2018, article id ICAS2018_0203Conference paper (Other academic)
    Abstract [en]

    Modelling and Simulation is key in aircraft system development. This paper presents a novel, multi-purpose, desktop simulator that can be used for detailed studies of the overall performance of coupled sub-systems, preliminary control design, and multidisciplinary optimization. Here, interoperability between industrially relevant tools for model development and simulation is established via the Functional Mockup Interface (FMI) and System Structure and Parametrization (SSP) standards. Robust and distributed simulation is enabled via the Transmission Line element Method (TLM). The advantages of the presented simulator are demonstrated via an industrially relevant use-case where simulations of pilot thermal comfort are coupled to Environmental Control System (ECS) steadystate and transient performance.

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  • 102.
    Imtiaz, Nasir
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics.
    CFD simulation of dip-lubricated single-stage gearboxes through coupling of multiphase flow and multiple body dynamics: an initial investigation2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Transmissions are an essential part of a vehicle powertrain. An optimally designed powertrain can result in energy savings, reduced environmental impact and increased comfort and reliability. Along with other components of the powertrain, efficiency is also a major concern in the design of transmissions. The churning power losses associated with the motion of gears through the oil represent a significant portion of the total power losses in a transmission and therefore need to be estimated. A lack of reliable empirical models for the prediction of these losses has led to the emergence of CFD (Computational Fluid Dynamics) as a means to (i) predict these losses and (ii) promote a deeper understanding of the physical phenomena responsible for theselosses in order to improve existing models.

    The commercial CFD solver STAR-CCM+ is used to investigate the oil distribution and the churning power losses inside two gearbox configurations namely an FZG (Technical Institute for the Study of Gears and Drive Mechanisms) gearbox and a planetary gearbox. A comparison of two motion handling techniques in STARCCM+ namely MRF (Moving Reference Frame) and RBM (Rigid Body Motion) models is made in terms of the accuracy of results and the computational requirements using the FZG gearbox. A sensitivity analysis on how the size of gap between the meshing gear teeth affects the flow and the computational requirements is also done using the FZG gearbox. Different modelling alternatives are investigated for the planetary gearbox and the best choices have been determined. The numerical simulations are solved in an unsteady framework where the VOF (Volume Of Fluid) multiphase model is used to track the interface between the immiscible phases. The overset meshing technique has been used to reconfigure the mesh at each time step.

    The results from the CFD simulations are presented and discussed in terms of the modelling choices made and their effect on the accuracy of the results. The MRF method is a cheaper alternative compared to the RBM model however, the former model does not accurately simulate the transient start-up and instead provides just a regime solution of the unsteady problem. As expected, the accuracy of the results suffers from having a large gap between the meshing gear teeth. The use of compressible ideal gas model for the air phase with a pressure boundary condition gives the optimum performance for the planetary gearbox. The outcomes can be used toeffectively study transmission flows using CFD and thereby improve the design of future transmissions for improved efficiency.

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  • 103.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Appendix A   Marker Sites and Datafile Columns2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. A.1-A.3Chapter in book (Other academic)
    Abstract [en]

    Datafiles (provided in this Appendix) associated with the six heart (H1-H6) study

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  • 104.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Appendix B NAC-MAD Composite Dataset2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. B.1-B.2Chapter in book (Other academic)
    Abstract [en]

    Here, we describe an attempt to model, as accurately as possible in 3-D space, the geometric relationship between the various components of the left ventricle, the mitral valve, and the aortic valve during systole and diastole.

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  • 105.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Appendix C Computational Details2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. C.1-C.6Chapter in book (Other academic)
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  • 106.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Appendix D Mitral Valve Animations2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. D.1-D.1Chapter in book (Other academic)
    Abstract [en]

    The PowerPoint mitral valve animations in this Appendix can be accessed by double-clicking the filenames. Both side view (LEFT PANEL, looking from posterior to anterior) and top view (RIGHT PANEL, looking from base to apex) are provided. All graphs have Marker #22 at the origin, Marker #1 on the Z-axis, and Marker #18 in the X-Z plane. The animations can be stepped forward with the right arrow and backwards with the left arrow with time-steps of 16.67 ms. The left ventricular pressure associated with each time step is indicated by the black dot on the LVP curve imbedded in the graph. Hit Escape to exit each animation. The H1-H6 datasets are located in Appendix A.

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  • 107.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Appendix E COM Studies2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. E.1-E.1Chapter in book (Other academic)
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  • 108.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Appendix F Flap Studies2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. F.1-F.3Chapter in book (Other academic)
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  • 109.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Appendix P Pull Study Markers, Datasets, Protocal Schematic2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. P.1-P.2Chapter in book (Other academic)
    Abstract [en]

    The PULL STUDY (see results in Chapter 28) was designed to assess the effect of posterior leaflet pressure on anterior leaflet edge geometry in the closed valve. Figure P1 shows the marker array and coordinate system used in this study.

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  • 110.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Appendix S SOD and DOS Studies2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. S.1-S.8Chapter in book (Other academic)
    Abstract [en]

    in two views of S2 sod04r02. Table S.2 defines the DOS marker anatomical locations and Figure S.3 illustrates these locations in D5 dos21r01. Table S.3 defines the markers delineating the space-filling tetrahedral for volume calculations. Figures S.4A-F display these tetrahedral within the left atrium and left ventricle of SOD hearts S1, S2, S3, S7, S9, and S10.

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  • 111.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 01 Anatomy and Marker Sites2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 1.1-1.3Chapter in book (Other academic)
    Abstract [en]

    Figure 1.1 is a view from a 3-D rendering of systolic geometry for the left ventricle, mitral valve, and aortic valve, computed as a composite from two experiments involving precise measurement of 83 marker sites. The methods used to obtain this 3-D dataset, including the full dataset file, are outlined in Appendix B. Note that in this systolic rendering, the aortic valve is open and the mitral valve is closed.

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  • 112.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 02 Fibrous Mitral Annulus2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 2.1-2.2Chapter in book (Other academic)
    Abstract [en]

    A fibrous collagen wedge, pointing toward the left ventricle, separates the mitral valve and left atrium from the aortic valve. The portion of this wedge between the mitral and aortic valves is known as the aortic mitral curtain or the intervalvular fibrous curtain.

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  • 113.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 03 Fibrous Annulus-Papillary Tip-LV Relationship2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 3.1-3.12Chapter in book (Other academic)
    Abstract [en]

    Figure 3.1 illustrates the geometric relationships between the LFT (Marker#29), APT (Marker#31), SH (Marker#22), RFT (Marker#24), and PPT (Marker#33) for diastole (left panel) and systole (right panel).

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  • 114.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 04 Anterior Leaflet Trampolines2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 4.1-4.5Chapter in book (Other academic)
    Abstract [en]

    In this chapter, we explore one of their likely functions. In future chapters, we examine additional functions. 

    A trampoline is a device that stretches a material taut with forces from peripheral radial springs. Here, we suggest that one of the functions of the anterior and posterior strut complexes is to stretch two anterior leaflet regions into a specific taut configuration at a specific time in the cardiac cycle.

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  • 115.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 05 Anterior Leaflet Mobility2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 5.1-5.8Chapter in book (Other academic)
    Abstract [en]

    In this chapter, we pull back and look at displacements throughout the cardiac cycle of the entire anterior leaflet, this time with respect to a plane formed by the saddlehorn and the two papillary tips (i.e. APT-SH-PPT).

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  • 116.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 06 Anterior Leaflet Curvatures2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 6.1-6.6Chapter in book (Other academic)
    Abstract [en]

    Anterior leaflet circumferential and radial curvatures were quantified in the six hearts as described in Appendix C. In brief, for each frame a best-fit plane was fit to all the anterior leaflet markers, including the trigonal hinge markers. Coordinate X-Y basis vectors were established in this plane and radial curvature was defined from the radius of a circle passing through the X-Z coordinates of radial marker triplets in this coordinate system (roughly perpendicular to the line connecting the LFT-RFT markers) and circumferential curvature defined from the radius of the circle passing through the Y-Z coordinates of circumferential marker triplets (roughly parallel to the line connecting the LFT-RFT markers). As defined in this fashion, positive curvature was concave to the LV, negative curvature was convex to the LV.

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  • 117.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 07 Anterior Leaflet Chordal Safety Net2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 7.1-7.4Chapter in book (Other academic)
    Abstract [en]

    In this chapter, we provide evidence for another important role for the strut chordae, namely, to prevent the anterior mitral leaflet, particularly its leading edge, from encroaching beyond a certain point into the LV outflow tract during LV filling.

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  • 118.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 08 Anterior Leaflet Shapes2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 8.1-8.8Chapter in book (Other academic)
    Abstract [en]

    Figures 8.1A-F display the anterior leaflet shape in each of the six hearts (H1-H6) during six key times during a representative cardiac cycle in each heart: T1 at the time of peak LV diastolic inflow; T2 at the onset of LVP increase preceding IVC; T3 at MV closing; T4 at the time of peak LV systolic outflow; T5 as MV is just beginning to open; and T6 a few frames after T5 at a time of maximum leaflet opening shape change.

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  • 119.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 09 Anterior leaflet Systolic Shape Invariance2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 9.1-9.11Chapter in book (Other academic)
    Abstract [en]

    Leaflet shape change in each heart was quantified by fitting (as described in Appendix C) a best-fit plane to all anterior leaflet markers for each frame (f) in the three consecutive beats studied. The distance (Z) from each anterior leaflet marker (m) to this plane in each frame Z(f,m) was then obtained. A systolic average, Zavg(m), was then obtained for each leaflet marker using all frames from mitral valve closing (MVC) to opening (MVO) for all three beats. For each frame, and each marker, the difference Z(f,m)-Zavg(m) was then computed and squared. The square root of the mean of these differences for all markers was then obtained for each frame as Zrms(f).

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  • 120.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 10 Anterior Leaflet Area2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 10.1-10.3Chapter in book (Other academic)
    Abstract [en]

    Anterior leaflet area was calculated using the Matlab algorithm given in Appendix C. For each frame in each heart, this algorithm fits a surface to all the anterior leaflet markers shown in Figure 1.2, tiles this surface with a fine mesh of rectangular elements with dimensions dx by dy, computes the area of each element as dx*dy, then sums all these areas to arrive at the total leaflet surface area. Tests of this algorithm showed that it is capable of measuring the surface area of a half sphere to within 1%.

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  • 121.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 11 Anterior Leaflet Strains2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 11.1-11.2Chapter in book (Other academic)
    Abstract [en]

    In this chapter, we attempt to better understand the underlying basis for this very small systolic area change.

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  • 122.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 12 Mitral LV Relationship2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 12.1-12.7Chapter in book (Other academic)
    Abstract [en]

    Figures 12.1-12.6 show the geometric relationships between the left ventricle and the mitral valve components for hearts H1-H6. The view is from the right fibrous trigone towards the left fibrous trigone, i.e., from the posterior wall of the LV towards the anterior wall. The best fit anterior leaflet plane is clamped to the X-Y axis for both the top frame (maximum LV inflow) and the bottom frame (maximum left ventricular pressure). LV markers #1-4 and # 8-13 are subepicardial; septal markers #5-7 are endocardial. The outflow tract is at lower right in each figure.

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  • 123.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 13 Anterior Leaflet LV Position2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 13.1-13.3Chapter in book (Other academic)
    Abstract [en]

    In this chapter we assess the variability of the 3-D position of this rigid leaflet within the left ventricular chamber throughout ventricular ejection.

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  • 124.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 14 Annular Size Variation2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 14.1-14.3Chapter in book (Other academic)
    Abstract [en]

    In this chapter, we visualize the valve along the Z-axis for the six hearts H1-H6, looking from the left atrium toward the left ventricle, clamping the best-fit annular plane to the X-Y axis. All scales are in mm.

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  • 125.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 15 Annular and Anterior Leaflet Area and Perimeter2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 15.1-15.4Chapter in book (Other academic)
    Abstract [en]

    Figure 15.1 shows mitral annular and anterior leaflet areas throughout sequential cardiac cycles for hearts H1-H6. The mitral annular area displayed in these figures is the projected annular area in the X-Y plane with the best-fit annular plane clamped to the X-Y axis for each frame. It is calculated as the sum of all the triangular areas from adjacent annular marker projections to the projection of the annular midpoint in that frame.

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  • 126.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 16 LV-Mitral Annular Coupling2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 16.1-16.8Chapter in book (Other academic)
    Abstract [en]

    The mitral leaflets hinges define the mitral annulus, thus changes in mitral annular dimensions impact leaflet opening, closing, and coaptation. At least six forces influence mitral annular dimensions, including left ventricular pressure, left atrial pressure, left heart blood flow, left atrial contraction, left ventricular contraction, and mitral chordae. In this chapter we postulate a working hypothesis concerning the impact of these forces on mitral annular dimensions throughout the cardiac cycle.

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  • 127.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 17 Mitral Annular Flexion2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 17.1-17.10Chapter in book (Other academic)
    Abstract [en]

    Itoh et al.1 have pointed out that the mitral annulus can be considered as a hinged structure, with the hinge located roughly along a line between the left (Marker #29, LFT) and right (Marker #24, RFT) fibrous trigones. This hinge, separating the contractile and non-contractile portions of the annulus, can be seen in Figures 17.1 and 17.2 (see captions for the views displayed in these figures). Although the studies described here were conducted in different hearts and employed a different geometric approach to data analysis than those of Itoh et al., the findings described here are consistent with theirs and should be considered as an extension of their findings which should be consulted for a very thorough discussion of this topic.

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  • 128.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 18 Annular and Leaflet Shape and Planarity2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 18.1-18.3Chapter in book (Other academic)
    Abstract [en]

    Annular shape change in each heart was quantified by fitting (as described in Appendix C) a best-fit plane to all annulus markers (#15-#30) for each frame (f) during the three consecutive beats studied. The distance (Z) from each annulus marker (m) to this plane in each frame Z(f,m) was then obtained and the standard deviation of Z(f,m) computed for that frame as ZSD(f). This process was repeated for just the contractile annulus markers (#16-#20; #24-#29). A systolic average, Zavg(m), was then obtained for all annulus markers using all frames from mitral valve closing (MVC) to opening (MVO) for all three beats. For each frame, and each marker, the difference Z(f,m)-Zavg(m) was then computed and squared. The square root of the mean of these differences for all markers was then obtained for each frame as Zrms(f).

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  • 129.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 19 Hinge Chordae2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 19.1-19.7Chapter in book (Other academic)
    Abstract [en]

    Each posterior leaflet annular radiopaque marker was surgically placed under direct observation at the posterior leaflet hinge points, where tissues associated with the left atrium and left ventricle meet the base of the leaflets. In this book, we define the mitral annulus as the locus of these hinge points, as did Angelini, et al.

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  • 130.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 20 Papillary Vectors2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 20.1-20.11Chapter in book (Other academic)
    Abstract [en]

    In this chapter (and the next) we analyze papillary mechanics for the F-series of experiments (See Appendix F), where papillary tip and base markers were placed inside the ventricle under direct visualization during cardiopulmonary bypass, allowing better measurement of papillary muscle lengths. In these hearts (F1-F11) the anterior papillary tip was assigned Marker #31, its base #32; the posterior papillary tip #33, its base #34. Muscle fibers are aligned along the long axes of papillary muscles, thus papillary muscle contractile force is exerted primarily along these axes. In this chapter, because the papillary muscle tips are connected via hinge chordae to the mitral annulus, we explore the orientation of these axes with respect to sites around the mitral annulus.

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  • 131.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 21 Papillary Forces2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 21.1-21.10Chapter in book (Other academic)
    Abstract [en]

    In this chapter, we combine the geometric data from our hearts F1-F11 (see Appendix F) with direct measurements of papillary and chordal forces by Salisbury et al.1, Nielsen et al.2, and Askov et al.3, to offer a general proposal concerning the role of these forces in the valvular-ventricular complex. Our speculation is based on the simplifying assumption of a single anterior and single posterior papillary muscle, recognizing that the actual situation, with multiple papillary tips, will be considerably more complex.

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  • 132.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 22 Papillary Chimera2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 22.1-22.5Chapter in book (Other academic)
    Abstract [en]

    This chapter analyzes papillary muscle mechanics for a mythical "PORVINE" heart created by superimposing PORcine and oVINE data. Porcine data were obtained from the LVP and papillary force curves in Figure 3 of Askov et al.1, digitized and interpolated with a cubic spline function. Ovine data are from our F10 heart, selected solely because the F10 LVP waveform was very similar to the LVP curve shown in Askov et al.1 Systolic duration was roughly matched by assigning a sampling interval of 15 ms to the ovine data, rather than the actual sampling interval of 16.67 ms. The porcine data were then sampled at these same 15 ms intervals. The resulting LVP, papillary force, and papillary length curves are shown in Figure 22.1, with magnitudes scaled or translated, as necessary, to fit the <0-9> ordinate. Additional ovine data, with time- but no magnitude-scaling, are shown in Figures 22.2, 22.5, and 22.6. Figure 22.7 shows the original data used to construct Figure 22.1.

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  • 133.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 23 Posterior Mitral Leaflet Anatomy and Marker Sites2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 23.1-23.3Chapter in book (Other academic)
    Abstract [en]

    In this and the next several chapters we conduct a more complete study of the dynamics of the posterior leaflet(s) employing datasets from hearts with 9 markers on the posterior leaflet edges and 10 markers on the anterior leaflet. These datasets and animations arising from them are given in Appendix E.

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  • 134.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 24 Posterior Leaflet Open2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 24.1-24.3Chapter in book (Other academic)
    Abstract [en]

    We begin by examining the maximum extent of posterior leaflet opening relative to the mitral annulus. To view this, in each sample frame we performed a translation to place Marker #22 at the origin, perform 2 rotations to place Marker #18 on the x-axis, then performed a final rotation to place anterior commissure Marker #16 into the x-y plane. This placed the mitral annulus into the x-y plane (to very close approximation) at each sample time. We then view the resulting mitral valve geometry along the z-axis, looking from the left atrium toward the left ventricle. Appendix E provides frame-by-frame animations showing the geometry of the mitral valve as described by three-dimensional cubic splines passing through connected marker locations during a representative beat (from maximum LVP in one beat to maximum LVP in the following beat) for the hearts studied in this fashion.

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  • 135.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 25 Posterior Leaflet Closed2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 25.1-25.4Chapter in book (Other academic)
    Abstract [en]

    In Chapter 24 we noted that the posterior leaflet edge perimeter changes by a mean value of 32 mm throughout the cardiac cycle, while the mitral annular perimeter changes by 13 mm and the anterior leaflet perimeter by only 7 mm. This suggests the possibility that the posterior leaflet may play a disproportionate role in mitral valve opening and closing. In this chapter, we begin to explore this possibility.

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  • 136.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 26 Posterior Leaflet Pleats and Scallops2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 26.1-26.3Chapter in book (Other academic)
    Abstract [en]

    In Chapter 25 we noted that the posterior leaflet regions in the vicinity of Markers #5 and 6 and #9 and 11 were undergoing consistently large dimensional changes with valve opening and closing in each of the three hearts studied, and thus might be considered as prime candidates for the large changes of the posterior leaflet perimeter throughout the cardiac cycle. In this chapter we explore the kinematics of these regions in greater detail. Again, we provide Figure 26.1 as a reference for marker placement in these studies.

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  • 137.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 27 Coaptation2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 27.1-27.3Chapter in book (Other academic)
    Abstract [en]

    In Chapter 26 we identified two major pleats at the P1/P2 and P2/P3 junctions of the posterior leaflet, characterized their kinematics throughout the cardiac cycle, and approximated their surfaces with two filled (red and blue) triangular surfaces. These triangles, however, are only intended as a visualization device; we know that the actual pleats in the closed valve would bow inward toward one another as systolic left ventricular pressure acts on their outer ventricular surfaces to press their convex faces tightly together. We cannot appreciate such curvature in these studies, however, because of the limited spatial resolution of our sparse marker arrays.

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  • 138.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 28 Anterior Leaflet Independence2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 28.1-28.8Chapter in book (Other academic)
    Abstract [en]

    This chapter discusses the PULL STUDY that was designed to assess the impact of posterior leaflet coaptation pressure on anterior leaflet edge geometry in the closed valve. Figure 28.1 shows the marker locations and coordinate system used in this study. Table 28.1 identifies the datasets associated with the CONTROL and PULL runs for the three technically-satisfactory experiments analyzed (Appendix P provides these datasets). Figure 28.2 illustrates the protocol schematically.

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  • 139.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 29 Anterior Leaflet Stiffness2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 29.1-29.7Chapter in book (Other academic)
    Abstract [en]

    In Chapters 09 and 13 we showed that the anterior leaflet in the closed valve maintains a nearly invariant shape and position in the ventricle as the leaflet is subjected to the large and variable trans-leaflet pressures in the beating heart. This implies that the leaflets must be quite stiff ̶ and this stiffness depends on leaflet shape, boundary conditions, and elastic moduli.

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  • 140.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 30 Active Anterior Leaflet2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 30.1-30.3Chapter in book (Other academic)
    Abstract [en]

    Mitral valve leaflets have long been considered as passive flaps. The findings described in Chapter 29 suggest otherwise, but the possibility that the large stiffness of the anterior leaflet arises simply from leaflet residual strains that place passive leaflet elastic elements into the post-transitional nonlinear region of their stress-strain curves must be considered. In the nonlinear stress-strain curves obtained by May-Newman and Yin1 from excised mitral leaflets (Figure 29.1) this requires residual stretch of roughly 15% or more for the anterior leaflet.

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  • 141.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 31  Valvular Interstitial Cells2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 31.1-31.1Chapter in book (Other academic)
    Abstract [en]

    The stiffening "twitch" of the annular half of the anterior mitral leaflet at the beginning of each beat likely arises from P-wave-stimulated, β-dependent, neurally-insensitive myocytes located in this region. The source of the ubiquitous, β-independent, neurally-sensitive, steady-state stiffness "tone" of the entire anterior leaflet is less clear, but may involve contractile Valvular Interstitial Cells (VICs) bound to leaflet collagen by α2β1 integrins, as discussed by Stephens et al.

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  • 142.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 31  Valvular Interstitial Cells2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 31.1-31.1Chapter in book (Other academic)
    Abstract [en]

    The stiffening "twitch" of the annular half of the anterior mitral leaflet at the beginning of each beat likely arises from P-wave-stimulated, β-dependent, neurally-insensitive myocytes located in this region. The source of the ubiquitous, β-independent, neurally-sensitive, steady-state stiffness "tone" of the entire anterior leaflet is less clear, but may involve contractile Valvular Interstitial Cells (VICs) bound to leaflet collagen by α2β1 integrins, as discussed by Stephens et al.

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  • 143.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 32  Anterior Leaflet Perfusion2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 32.1-32.2Chapter in book (Other academic)
    Abstract [en]

    The anterior leaflet contains both sensory and motor nerves, striated and smooth muscle, VICs, and other metabolizing cell types, thus it is not surprising that blood vessels have been found in the leaflet body and chordae, although such findings have sometimes stirred controversy. Swanson et al.1 employed selective injections of fluorescein dye into the left anterior descending and circumflex coronary arteries of ovine hearts excised immediately after heparinization and cardioplegic arrest to assess potential leaflet perfusion patterns associated with such vessels.

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  • 144.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 33  Leaflet Angles and Separation2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 33.1-33.2Chapter in book (Other academic)
    Abstract [en]

    In this chapter we explore the opening and closing behavior of the anterior and posterior leaflets whose hinge regions define the mitral annulus.

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  • 145.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 34 Left Ventricular Flow2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 34.1-34.5Chapter in book (Other academic)
    Abstract [en]

    In this chapter we examine the relationship of anterior and posterior leaflet edge mobility to left ventricular inflow (quantified as described in Appendix C) and pressure.

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  • 146.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 36 Coaptation Repeatability and Rigidity2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 36.1-36.8Chapter in book (Other academic)
    Abstract [en]

    Competent mitral valve closure requires tight coaptation of the edge surfaces of the anterior and posterior leaflets. This chapter explores the precision with which specific sites on these surfaces are geometrically aligned at the beginning of each beat (repeatability) and the precision with which this alignment is maintained throughout left ventricular ejection (rigidity).

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  • 147.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 37: Four Balloons2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 37.1-37.7Chapter in book (Other academic)
    Abstract [en]

    In this chapter, we metaphorically characterize the mitral leaflets as segments of four inflated balloons pressed together on the ventricular side of the mitral annulus in such a geometric configuration as to preclude their crowding through the mitral annulus into the left atrium. The greater the inflation pressure (LVP), the more firmly the balloon interfaces press together, the more impossible it becomes to crowd this assemblage through the annulus.

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  • 148.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 38 The Commissures2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 38.1-38.5Chapter in book (Other academic)
    Abstract [en]

    The anterior commissure is the junctional region between the anterior leaflet and the P1 scallop of the posterior leaflet (Markers 1, 2, 3, and 16 in Figure 38.1; fold 3 in Figure 27.1). Figures 38.2 and 38.3 show individual frames from an animation of anterior commissure data during a representative heartbeat in COM07R04 with the valve closed, and open, respectively.

    The posterior commissure is the junctional region between the anterior leaflet and the P3 scallop of the posterior leaflet (Markers 12, 13, 14, and 20 in Figure 38.1; fold 4 in Figure 27.1). Figures 38.4 and 38.5 show Individual frames from an animation of posterior commissure data during the same heartbeat in COM07R04 with the valve closed, and open, respectively.

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  • 149.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 39 Suspends, Belt2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 39.1-39.7Chapter in book (Other academic)
    Abstract [en]

    In Chapter 36 we noted that the anterior leaflet edge is roughly fixed in position throughout systole and in Chapter 28 that this edge position is almost independent of its interaction with the posterior leaflet. This suggests that effective coaptation requires the posterior leaflet to conform tightly to the edge of the stiff anterior leaflet. In this chapter, again employing the data in Appendix E, we suggest that the posterior leaflet folds are important for this task.

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  • 150.
    Ingels, Jr, Neil B
    et al.
    Department of Cardiothoracic Surgery, Stanford University School of Medicine; Research Institute of the Palo Alto Medical Foundation, Palo Alto, USA.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Chapter 40 Leaflet Tent2016In: Mitral Valve Mechanics / [ed] Neil B Ingels, Jr and Matts Karlsson, Linköping University Electronic Press, 2016, p. 40.1-40.3Chapter in book (Other academic)
    Abstract [en]

    The concept of the closed mitral valve forming a tent-like structure is well-known in the literature. The mitral annulus forms the "floor" of the tent and the leaflets form the tent "walls" that extend from the annulus into the LV. In this chapter we build on this concept, utilizing concepts developed from our findings in earlier chapters based on 4-D marker data.

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