Journal article 1474 views
Determining the combined effect of the lymphatic valve leaflets and sinus on resistance to forward flow
Journal of Biomechanics, Volume: 48, Issue: 13, Pages: 3584 - 3590
Swansea University Author:
Raoul van Loon
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DOI (Published version): 10.1016/j.jbiomech.2015.07.045
Abstract
The lymphatic system is vital to a proper maintenance of fluid and solute homeostasis. Collecting lymphatics are composed of actively contracting tubular vessels segmented by bulbous sinus regions that encapsulate bi-leaflet check valves. Valve resistance to forward flow strongly influences pumping...
Published in: | Journal of Biomechanics |
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ISSN: | 0021-9290 |
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2015
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URI: | https://cronfa.swan.ac.uk/Record/cronfa24213 |
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<?xml version="1.0"?><rfc1807><datestamp>2018-05-18T15:29:41.9969348</datestamp><bib-version>v2</bib-version><id>24213</id><entry>2015-11-09</entry><title>Determining the combined effect of the lymphatic valve leaflets and sinus on resistance to forward flow</title><swanseaauthors><author><sid>880b30f90841a022f1e5bac32fb12193</sid><ORCID>0000-0003-3581-5827</ORCID><firstname>Raoul</firstname><surname>van Loon</surname><name>Raoul van Loon</name><active>true</active><ethesisStudent>false</ethesisStudent></author></swanseaauthors><date>2015-11-09</date><deptcode>MEDE</deptcode><abstract>The lymphatic system is vital to a proper maintenance of fluid and solute homeostasis. Collecting lymphatics are composed of actively contracting tubular vessels segmented by bulbous sinus regions that encapsulate bi-leaflet check valves. Valve resistance to forward flow strongly influences pumping performance. However, because of the sub-millimeter size of the vessels with flow rates typically &#60;1 ml/h and pressures of a few cmH2O, resistance is difficult to measure experimentally. Using a newly defined idealized geometry, we employed an uncoupled approach where the solid leaflet deflections of the open valve were computed and lymph flow calculations were subsequently performed. We sought to understand: 1) the effect of sinus and leaflet size on the resulting deflections experienced by the valve leaflets and 2) the effects on valve resistance to forward flow of the fully open valve. For geometries with sinus-to-root diameter ratios &#62;1.39, the average resistance to forward flow was 0.95×106 [g/(cm4 s)]. Compared to the viscous pressure drop that would occur in a straight tube the same diameter as the upstream lymphangion, valve leaflets alone increase the pressure drop up to 35%. However, the presence of the sinus reduces viscous losses, with the net effect that when combined with leaflets the overall resistance is less than that of the equivalent continuing straight tube. Accurately quantifying resistance to forward flow will add to the knowledge used to develop therapeutics for treating lymphatic disorders and may eventually lead to understanding some forms of primary lymphedema.</abstract><type>Journal Article</type><journal>Journal of Biomechanics</journal><volume>48</volume><journalNumber>13</journalNumber><paginationStart>3584</paginationStart><paginationEnd>3590</paginationEnd><publisher/><issnPrint>0021-9290</issnPrint><keywords/><publishedDay>15</publishedDay><publishedMonth>10</publishedMonth><publishedYear>2015</publishedYear><publishedDate>2015-10-15</publishedDate><doi>10.1016/j.jbiomech.2015.07.045</doi><url/><notes/><college>COLLEGE NANME</college><department>Biomedical Engineering</department><CollegeCode>COLLEGE CODE</CollegeCode><DepartmentCode>MEDE</DepartmentCode><institution>Swansea University</institution><apcterm/><lastEdited>2018-05-18T15:29:41.9969348</lastEdited><Created>2015-11-09T16:44:43.0418492</Created><path><level id="1">Faculty of Science and Engineering</level><level id="2">School of Engineering and Applied Sciences - Biomedical Engineering</level></path><authors><author><firstname>John T.</firstname><surname>Wilson</surname><order>1</order></author><author><firstname>Raoul</firstname><surname>van Loon</surname><orcid>0000-0003-3581-5827</orcid><order>2</order></author><author><firstname>Wei</firstname><surname>Wang</surname><order>3</order></author><author><firstname>David C.</firstname><surname>Zawieja</surname><order>4</order></author><author><firstname>James E.</firstname><surname>Moore</surname><order>5</order></author></authors><documents/><OutputDurs/></rfc1807> |
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2018-05-18T15:29:41.9969348 v2 24213 2015-11-09 Determining the combined effect of the lymphatic valve leaflets and sinus on resistance to forward flow 880b30f90841a022f1e5bac32fb12193 0000-0003-3581-5827 Raoul van Loon Raoul van Loon true false 2015-11-09 MEDE The lymphatic system is vital to a proper maintenance of fluid and solute homeostasis. Collecting lymphatics are composed of actively contracting tubular vessels segmented by bulbous sinus regions that encapsulate bi-leaflet check valves. Valve resistance to forward flow strongly influences pumping performance. However, because of the sub-millimeter size of the vessels with flow rates typically <1 ml/h and pressures of a few cmH2O, resistance is difficult to measure experimentally. Using a newly defined idealized geometry, we employed an uncoupled approach where the solid leaflet deflections of the open valve were computed and lymph flow calculations were subsequently performed. We sought to understand: 1) the effect of sinus and leaflet size on the resulting deflections experienced by the valve leaflets and 2) the effects on valve resistance to forward flow of the fully open valve. For geometries with sinus-to-root diameter ratios >1.39, the average resistance to forward flow was 0.95×106 [g/(cm4 s)]. Compared to the viscous pressure drop that would occur in a straight tube the same diameter as the upstream lymphangion, valve leaflets alone increase the pressure drop up to 35%. However, the presence of the sinus reduces viscous losses, with the net effect that when combined with leaflets the overall resistance is less than that of the equivalent continuing straight tube. Accurately quantifying resistance to forward flow will add to the knowledge used to develop therapeutics for treating lymphatic disorders and may eventually lead to understanding some forms of primary lymphedema. Journal Article Journal of Biomechanics 48 13 3584 3590 0021-9290 15 10 2015 2015-10-15 10.1016/j.jbiomech.2015.07.045 COLLEGE NANME Biomedical Engineering COLLEGE CODE MEDE Swansea University 2018-05-18T15:29:41.9969348 2015-11-09T16:44:43.0418492 Faculty of Science and Engineering School of Engineering and Applied Sciences - Biomedical Engineering John T. Wilson 1 Raoul van Loon 0000-0003-3581-5827 2 Wei Wang 3 David C. Zawieja 4 James E. Moore 5 |
title |
Determining the combined effect of the lymphatic valve leaflets and sinus on resistance to forward flow |
spellingShingle |
Determining the combined effect of the lymphatic valve leaflets and sinus on resistance to forward flow Raoul van Loon |
title_short |
Determining the combined effect of the lymphatic valve leaflets and sinus on resistance to forward flow |
title_full |
Determining the combined effect of the lymphatic valve leaflets and sinus on resistance to forward flow |
title_fullStr |
Determining the combined effect of the lymphatic valve leaflets and sinus on resistance to forward flow |
title_full_unstemmed |
Determining the combined effect of the lymphatic valve leaflets and sinus on resistance to forward flow |
title_sort |
Determining the combined effect of the lymphatic valve leaflets and sinus on resistance to forward flow |
author_id_str_mv |
880b30f90841a022f1e5bac32fb12193 |
author_id_fullname_str_mv |
880b30f90841a022f1e5bac32fb12193_***_Raoul van Loon |
author |
Raoul van Loon |
author2 |
John T. Wilson Raoul van Loon Wei Wang David C. Zawieja James E. Moore |
format |
Journal article |
container_title |
Journal of Biomechanics |
container_volume |
48 |
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13 |
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3584 |
publishDate |
2015 |
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Swansea University |
issn |
0021-9290 |
doi_str_mv |
10.1016/j.jbiomech.2015.07.045 |
college_str |
Faculty of Science and Engineering |
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facultyofscienceandengineering |
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Faculty of Science and Engineering |
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facultyofscienceandengineering |
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Faculty of Science and Engineering |
department_str |
School of Engineering and Applied Sciences - Biomedical Engineering{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Engineering and Applied Sciences - Biomedical Engineering |
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description |
The lymphatic system is vital to a proper maintenance of fluid and solute homeostasis. Collecting lymphatics are composed of actively contracting tubular vessels segmented by bulbous sinus regions that encapsulate bi-leaflet check valves. Valve resistance to forward flow strongly influences pumping performance. However, because of the sub-millimeter size of the vessels with flow rates typically <1 ml/h and pressures of a few cmH2O, resistance is difficult to measure experimentally. Using a newly defined idealized geometry, we employed an uncoupled approach where the solid leaflet deflections of the open valve were computed and lymph flow calculations were subsequently performed. We sought to understand: 1) the effect of sinus and leaflet size on the resulting deflections experienced by the valve leaflets and 2) the effects on valve resistance to forward flow of the fully open valve. For geometries with sinus-to-root diameter ratios >1.39, the average resistance to forward flow was 0.95×106 [g/(cm4 s)]. Compared to the viscous pressure drop that would occur in a straight tube the same diameter as the upstream lymphangion, valve leaflets alone increase the pressure drop up to 35%. However, the presence of the sinus reduces viscous losses, with the net effect that when combined with leaflets the overall resistance is less than that of the equivalent continuing straight tube. Accurately quantifying resistance to forward flow will add to the knowledge used to develop therapeutics for treating lymphatic disorders and may eventually lead to understanding some forms of primary lymphedema. |
published_date |
2015-10-15T03:28:40Z |
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1763751095886151680 |
score |
11.021648 |