title: A 1D pulse wave propagation model of the hemodynamics of calf muscle pump function.
abstract: The calf muscle pump is a mechanism which increases venous return and thereby compensates for the fluid shift towards the lower body during standing. During a muscle contraction, the embedded deep veins collapse and venous return increases. In the subsequent relaxation phase, muscle perfusion increases due to increased perfusion pressure, as the proximal venous valves temporarily reduce the distal venous pressure (shielding). The superficial and deep veins are connected via perforators, which contain valves allowing flow in the superficial-to-deep direction. The aim of this study is to investigate and quantify the physiological mechanisms of the calf muscle pump, including the effect of venous valves, hydrostatic pressure, and the superficial venous system. Using a one-dimensional pulse wave propagation model, a muscle contraction is simulated by increasing the extravascular pressure in the deep venous segments. The hemodynamics are studied in three different configurations: a single artery-vein configuration with and without valves and a more detailed configuration including a superficial vein. Proximal venous valves increase effective venous return by 53% by preventing reflux. Furthermore, the proximal valves shielding function increases perfusion following contraction. Finally, the superficial system aids in maintaining the perfusion during the contraction phase and reduces the refilling time by 37%.
authors.affiliation: Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany.|Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: J M T
authors.initials: JM
authors.lastname: Keijsers
authors.affiliation: Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany.
authors.forename: C A D
authors.initials: CA
authors.lastname: Leguy
authors.affiliation: Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.|Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands.
authors.forename: W
authors.initials: W
authors.lastname: Huberts
authors.affiliation: Medical Physics Group, Department of Cardiovascular Science, University of Sheffield, Sheffield, UK.|INSIGNEO Institute for in silico Medicine, University of Sheffield, Sheffield, UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: Narracott
authors.affiliation: Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Rittweger
authors.affiliation: Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors.forename: F N
authors.initials: FN
authors.lastname: van de Vosse
mesh_terms: D002320:Cardiovascular Physiological Phenomena; D003198:Computer Simulation; D006801:Humans; D006874:Hydrostatic Pressure; D007866:Leg / Q000098:blood supply* / Q000502:physiology*; D008955:Models, Cardiovascular; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000502:physiology*; D063177:Pulse Wave Analysis; D012039:Regional Blood Flow / Q000502:physiology*
keywords: 1D pulse wave propagation; collapsible vein; gravity; muscle pump; orthostatic intolerance; venous valves