One might suspect the answer to this question has something to do with deep vein thrombosis, the blood clotting that can occur under pressure at altitude. But this would be wrong. An EU-funded research project is applying a technology used to measure airflow over plane wings to help learn more about the effects of medical implants on blood flow.
Researchers from Italy, Germany and Greece have optimised a Particle Image Velocimetry (PIV) system – the kind traditionally used to improve the aerodynamics of aircraft wings – to make it capable of accurately measuring the effects of medical implants on blood flow, according to a recent IST Results story. Their work will help manufacturers to improve designs for medical devices, such as heart valves and pumps, and doctors detecting and correcting any implant side effects.
|As many as three full football stadiums a year receive medical implants each year worldwide.|
Fabrizio Lagasco of D'Appolonia S.p.A., who is coordinating the IST programme-funded SMART-PIV project, predicts that the system is likely to have a significant impact on the heart device market over the coming years. “It could revolutionise heart treatments,” he told IST Results.
The SMART-PIV system – which stands for ‘Development Of An Interactive Integrated P.i.v. System Based On Miniaturised Optical Sensor Technology For Implantable Biomedical Devices Design' – combines optimised PIV hardware with advanced image processing and software over a parallel computing subsystem. Although ultrasound scans allow doctors to view potential problems in the heart itself – and in the nearby circulatory system – detailed analysis of blood-flow problems following modification by artificially implanted devices is harder. Implanting medical devices into animals can prove that a device works, but such in vivo trials are time-consuming, costly and not necessarily a true indicator of whether the device would take in a human.
For example, ventricular-assist devices (VADs) – battery operated pumps that support a failing left ventricle and help supply blood to the rest of the body – used to buy patients time until a heart donor can be found. But even in the best-case scenario they only extend a patient's life by up to two years and frequently by just a few months. So, although implants prolong the lives of patients with cardiovascular disease, reducing their side effects through improved in vitro design would also increase their quality of life and chances of long-term survival.
By applying PIV technology in their development, Lagasco expects it would be possible to greatly enhance their performance and grant patients more time to obtain a transplant.
To the heart of the matter
Complications are widespread among patients who receive implants. People receiving heart valves, which are implanted in around 225 000 patients worldwide each year, often require anticoagulant drugs to prevent clotting and thrombosis. But these drugs raise the risk of bleeding. Stents, which are used to prop open blocked arteries, pose similar problems and can lead to infections.
“With so few donors available compared to the people who need new hearts, the number of people with implants is only going to continue increasing,” Lagasco laments. And cardiovascular disease is already Europe's number one killer.
The project's PIV system hopes to reverse this trend. Its miniaturised optical sensor technology uses ultra-thin laser light sheets to capture images of the fluid dynamics of blood flowing through implanted devices. Numerical analysis is carried out on the images in a parallel computing subsystem allowing device designers or doctors to detect problems with the blood flow, such as high velocity gradients that can cause blood cell damage, or low velocity that could lead to thrombosis or coagulation.
Based on trials carried out by the SMART-PIV's seven partner organisations, which were co-funded by the Fifth Research Framework Programme to the tune of €2.1 million, the analysis can be performed in under a day in 80% of cases and in less than two days in all cases. “As computer processing power increases, we estimate that, within two years, the analysis could be performed in two to three hours, Lagasco notes, compared with the weeks or months it can take to obtain results using traditional PIV systems.
An easy-to-use graphical user interface ensures that the system can be used by doctors and others who are not necessarily experts in PIV technology. Having tested the system in vitro during the three-year project, the consortium is now planning to develop and evaluate it further in trials involving a medical device manufacturer.
“The commercial possibilities for the system are […] extensive and a product based on the project results will probably be in use within the next few years,” predicts the project coordinator. Despite finishing in May this year, the team continues to look for new ways to roll out their system. Scouts have been sent to investigate the market opportunities in alternative fields, such as defence and shipbuilding, he adds.