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Anatol J, García-Díaz M, Barrios-Collado C, Moneo-Fernández JA, Horvath M, Parra T, Castro-Ruiz F, Roche ET, Sierra-Pallares J. Experimental study of an asymmetric valveless pump to elucidate insights into strategies for pediatric extravascular flow augmentation. Sci Rep 2022; 12:22165. [PMID: 36550224 PMCID: PMC9780230 DOI: 10.1038/s41598-022-26524-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
Asymmetric pumping is a sub-category of valveless pumping in which a flexible tube is rhythmically compressed in the transverse symmetry plane. Due to the resulting asymmetry between the suction and discharge pipes, a net pumping head is achieved. Asymmetric pumping is regarded as one of the main mechanisms responsible for the Liebau effect in addition to impedance pumping. However, there remains a paucity of research surrounding the governing parameters of asymmetric pumping. Here, we conducted an experimental study of the performance of an asymmetric pump, with an aim to assess its potential for extravascular flow augmentation. A custom flexible latex tube and experimental platform were developed for this purpose. We tested various tube thicknesses and pinching frequencies. Our results demonstrate that the performance is within the range of physiological requirements for pediatric circulatory devices (~ 1 L/min and < 30 mmHg). We conclude that due to the absence of reverse flow and its mechanical simplicity, pure asymmetric pumping is promising for selected cardiovascular applications with less complexity than other valveless techniques.
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Affiliation(s)
- J. Anatol
- grid.5239.d0000 0001 2286 5329Departamento de Ingeniería Energética y Fluidomecánica and ITAP, Universidad de Valladolid, Paseo del Cauce 59, 47011 Valladolid, Spain
| | - M. García-Díaz
- grid.5239.d0000 0001 2286 5329Departamento de Ingeniería Energética y Fluidomecánica and ITAP, Universidad de Valladolid, Paseo del Cauce 59, 47011 Valladolid, Spain
| | - C. Barrios-Collado
- grid.5239.d0000 0001 2286 5329Departamento de Ingeniería Energética y Fluidomecánica and ITAP, Universidad de Valladolid, Paseo del Cauce 59, 47011 Valladolid, Spain
| | - J. A. Moneo-Fernández
- grid.5239.d0000 0001 2286 5329Departamento de Ingeniería Energética y Fluidomecánica and ITAP, Universidad de Valladolid, Paseo del Cauce 59, 47011 Valladolid, Spain
| | - M. Horvath
- grid.116068.80000 0001 2341 2786Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - T. Parra
- grid.5239.d0000 0001 2286 5329Departamento de Ingeniería Energética y Fluidomecánica and ITAP, Universidad de Valladolid, Paseo del Cauce 59, 47011 Valladolid, Spain
| | - F. Castro-Ruiz
- grid.5239.d0000 0001 2286 5329Departamento de Ingeniería Energética y Fluidomecánica and ITAP, Universidad de Valladolid, Paseo del Cauce 59, 47011 Valladolid, Spain
| | - E. T. Roche
- grid.116068.80000 0001 2341 2786Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139 USA ,grid.116068.80000 0001 2341 2786Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - J. Sierra-Pallares
- grid.5239.d0000 0001 2286 5329Departamento de Ingeniería Energética y Fluidomecánica and ITAP, Universidad de Valladolid, Paseo del Cauce 59, 47011 Valladolid, Spain
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Sarvazyan N. Building Valveless Impedance Pumps From Biological Components: Progress and Challenges. Front Physiol 2022; 12:770906. [PMID: 35173623 PMCID: PMC8842681 DOI: 10.3389/fphys.2021.770906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 12/08/2021] [Indexed: 01/20/2023] Open
Abstract
Valveless pumping based on Liebau mechanism entails asymmetrical positioning of the compression site relative to the attachment sites of the pump's elastic segment to the rest of the circuit. Liebau pumping is believed to play a key role during heart development and be involved in several other physiological processes. Until now studies of Liebau pump have been limited to numerical analyses, in silico modeling, experiments using non-biological elements, and a few indirect in vivo measurements. This review aims to stimulate experimental efforts to build Liebau pumps using biologically compatible materials in order to encourage further exploration of the fundamental mechanisms behind valveless pumping and its role in organ physiology. The covered topics include the biological occurrence of Liebau pumps, the main differences between them and the peristaltic flow, and the potential uses and body sites that can benefit from implantable valveless pumps based on Liebau principle. We then provide an overview of currently available tools to build such pumps and touch upon limitations imposed by the use of biological components. We also talk about the many variables that can impact Liebau pump performance, including the concept of resonant frequencies, the shape of the flowrate-frequency relationship, the flow velocity profiles, and the Womersley numbers. Lastly, the choices of materials to build valveless impedance pumps and possible modifications to increase their flow output are briefly discussed.
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Affiliation(s)
- Narine Sarvazyan
- Department of Pharmacology and Physiology, School of Medicine and Health Science, The George Washington University, Washington, DC, United States
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