Measurement of pulsatile haemodynamic forces in a model of a bifurcated stent graft for abdominal aortic aneurysm repair

S.N. Zhou, T.V. How, R.A. Black, S.R. Vallabhanein, R. McWilliams, J.A. Brennan

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

The longitudinal haemodynamic force (LF) acting on a bifurcated stent graft for abdominal aortic aneurysm repair has been estimated previously using a simple onedimensional analytical model based on the momentum equation which assumes steady flow of an inviscid fluid. Using an instrumented stent-graft model an experimental technique was developed to measure the LF under pulsatile flow conditions. The physical stent-graft model, with main trunk diameter of 30mm and limb diameters of 12mm, was fabricated from aluminium. Strain gauges were bonded on to the main trunk to determine the longitudinal strain which is related to the LF. After calibration, the model was placed in a pulsatile flow system with 40 per cent aqueous glycerol solution as the circulating fluid. The LF was determined using a Wheatstone bridge signal-conditioning circuit. The signals were averaged over 590 cardiac cycles and saved to a personal computer for subsequent processing. The LF was strongly dependent on the pressure but less so on the flowrate. The measured forces were higher than those predicted by the simplified mathematical model by about 6-18 per cent during the cardiac cycle. The excess measured forces are due to the viscous drag and the effect of pulsatile flow. The peak measured LF in this model of 30mm diameter may exceed the fixation force of some current clinical endovascular stent grafts.
Original languageEnglish
Pages (from-to)543-549
Number of pages7
JournalProceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine
Volume222
Issue number4
DOIs
Publication statusPublished - 1 Apr 2008

Fingerprint

Stents
Hemodynamics
Grafts
Repair
Pulsatile flow
Signal conditioning circuits
Fluids
Steady flow
Strain gages
Glycerol
Personal computers
Drag
Momentum
Calibration
Mathematical models
Aluminum
Processing

Keywords

  • migration
  • endovascular repair
  • strain gauges
  • bioengineering

Cite this

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abstract = "The longitudinal haemodynamic force (LF) acting on a bifurcated stent graft for abdominal aortic aneurysm repair has been estimated previously using a simple onedimensional analytical model based on the momentum equation which assumes steady flow of an inviscid fluid. Using an instrumented stent-graft model an experimental technique was developed to measure the LF under pulsatile flow conditions. The physical stent-graft model, with main trunk diameter of 30mm and limb diameters of 12mm, was fabricated from aluminium. Strain gauges were bonded on to the main trunk to determine the longitudinal strain which is related to the LF. After calibration, the model was placed in a pulsatile flow system with 40 per cent aqueous glycerol solution as the circulating fluid. The LF was determined using a Wheatstone bridge signal-conditioning circuit. The signals were averaged over 590 cardiac cycles and saved to a personal computer for subsequent processing. The LF was strongly dependent on the pressure but less so on the flowrate. The measured forces were higher than those predicted by the simplified mathematical model by about 6-18 per cent during the cardiac cycle. The excess measured forces are due to the viscous drag and the effect of pulsatile flow. The peak measured LF in this model of 30mm diameter may exceed the fixation force of some current clinical endovascular stent grafts.",
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Measurement of pulsatile haemodynamic forces in a model of a bifurcated stent graft for abdominal aortic aneurysm repair. / Zhou, S.N.; How, T.V.; Black, R.A.; Vallabhanein, S.R.; McWilliams, R.; Brennan, J.A.

In: Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine , Vol. 222, No. 4, 01.04.2008, p. 543-549.

Research output: Contribution to journalArticle

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AU - How, T.V.

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AU - McWilliams, R.

AU - Brennan, J.A.

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