Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Cardiovascular disease: The mechanics of prosthetic heart valves

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:

More articles from Medical Engineering:

nachricht Bern’s surgical procedure for brain tumours a world leader
03.11.2015 | Universitätsspital Bern

nachricht Siemens Healthcare introduces first Twin Robotic X-Ray system
29.10.2015 | Siemens AG

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Climate study finds evidence of global shift in the 1980s

Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.

Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...

Im Focus: Innovative Photovoltaics – from the Lab to the Façade

Fraunhofer ISE Demonstrates New Cell and Module Technologies on its Outer Building Façade

The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...

Im Focus: Lactate for Brain Energy

Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.

In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...

Im Focus: Laser process simulation available as app for first time

In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.

Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...

Im Focus: Quantum Simulation: A Better Understanding of Magnetism

Heidelberg physicists use ultracold atoms to imitate the behaviour of electrons in a solid

Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...

All Focus news of the innovation-report >>>



Event News

Fraunhofer’s Urban Futures Conference: 2 days in the city of the future

25.11.2015 | Event News

Gluten oder nicht Gluten? Überempfindlichkeit auf Weizen kann unterschiedliche Ursachen haben

17.11.2015 | Event News

Art Collection Deutsche Börse zeigt Ausstellung „Traces of Disorder“

21.10.2015 | Event News

Latest News

Siemens to supply 126 megawatts to onshore wind power plants in Scotland

27.11.2015 | Press release

Two decades of training students and experts in tracking infectious disease

27.11.2015 | Life Sciences

Coming to a monitor near you: A defect-free, molecule-thick film

27.11.2015 | Materials Sciences

More VideoLinks >>>