Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cardiovascular disease: The mechanics of prosthetic heart valves

21.12.2012
Computer simulations of blood flow through mechanical heart valves could pave the way for more individualized prosthetics
Every year, over 300,000 heart valve replacement operations are performed worldwide. Diseased valves are often replaced with mechanical heart valves (MHVs), which cannot yet be designed to suit each patient’s specific needs. Complications such as blood clots can occur, which can require patients to take blood-thinning medication.

To investigate why such complications occur, Vinh-Tan Nguyen at A*STAR’s Institute of High Performance Computing, Singapore, together with scientists at the National University of Singapore and institutions across the USA, have developed a new computer model to simulate the dynamics of blood flow through MHVs1.

“The current practice for heart valve replacement in patients is a one-size-fits-all approach where a patient is implanted with the best-fit valve available on the market,” explains Nguyen. “The valves are well designed for general physiological conditions, but may not be suitable for each individual’s particular heart condition.”

The researchers focused on the blood flow dynamics in a prosthetic valve known as a bileaflet MHV. This type of MHV contains two mobile leaflets, or gates, which are held in place by hinges. The leaflets open and close in response to blood flow pressures through the valve. Little is known about the effect that the hinged leaflets have on blood dynamics, although such designs are suspected of causing blood clots.

The computer model developed by Nguyen and his team simulates pressure flows through bileaflet MHVs by representing blood vessels as a computational mesh, where calculations are performed for individual blocks of the mesh. Their crucial advance was in enabling this mesh to move and evolve in response to the leaflet movements.

The researchers validated their computer model through laboratory experiments with a full 3D reproduction of the heart's circulation system. Particle imaging equipment allowed them to visualize the fluid dynamics under different scenarios including pulsatile flow, which follows the pattern of a typical cardiac cycle.

“We obtained good agreement between our computer simulations and the experiments in terms of the magnitude and velocity of blood flow through the leaflets,” states Nguyen. The researchers also found that leaflet hinges might play a vital role in clotting, because individual hinges have different tolerances that can disrupt normal blood flow and cause stress in the vein walls.

This research is a first crucial step in understanding the impact of MHVs on blood flow. “Ultimately we hope to provide doctors with a tool to evaluate blood flow dynamics and other related aspects in patients with newly implanted valves,” says Nguyen.

The A*STAR-affiliated researchers contributing to this research are from the Institute of High Performance Computing

Journal information

Nguyen, V.-T., Kuan, Y. H., Chen, P.-Y., Ge, L., Sotiropoulos, F. et al. Experimentally validated hemodynamics simulations of mechanical heart valves in three dimensions. Cardiovascular Engineering and Technology 3, 88–100 (2012)

A*STAR Research | Research asia research news
Further information:
http://www.a-star.edu.sg
http://www.researchsea.com
http://www.researchsea.com/html/article.php/eml/1/aid/7539/cid/3

More articles from Medical Engineering:

nachricht New imaging modality targets cholesterol in arterial plaque
14.06.2019 | SPIE--International Society for Optics and Photonics

nachricht Piedmont Atlanta first in Georgia to offer new minimally invasive treatment for emphysema
24.05.2019 | Pulmonx

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The hidden structure of the periodic system

The well-known representation of chemical elements is just one example of how objects can be arranged and classified

The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

Im Focus: Tube anemone has the largest animal mitochondrial genome ever sequenced

Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.

The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....

Im Focus: Tiny light box opens new doors into the nanoworld

Researchers at Chalmers University of Technology, Sweden, have discovered a completely new way of capturing, amplifying and linking light to matter at the nanolevel. Using a tiny box, built from stacked atomically thin material, they have succeeded in creating a type of feedback loop in which light and matter become one. The discovery, which was recently published in Nature Nanotechnology, opens up new possibilities in the world of nanophotonics.

Photonics is concerned with various means of using light. Fibre-optic communication is an example of photonics, as is the technology behind photodetectors and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Uncovering hidden protein structures

18.06.2019 | Life Sciences

Monitoring biodiversity with sound: how machines can enrich our knowledge

18.06.2019 | Life Sciences

Schizophrenia: Adolescence is the game-changer

18.06.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>